CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 AFRICA 103 Editorial Fascial plane regional anaesthesia techniques Renier Verbeek, Felipe Montoya, Justiaan LC Swanevelder 10.5830/CVJA-2022-034 Peri-operative pain management and a reduction in stress response to cardiac surgery has traditionally been accomplished with opioids, but these agents also have a negative effect on enhanced recovery after surgery (ERAS). Techniques based on reducing opioid use is associated with fewer side effects and earlier patient recovery. Increasing pressure to provide efficient patient care while improving patient outcomes has led to a recent surge in administering regional techniques for cardiac surgery as part of a multimodal pain management concept, with the overall goal to provide effective and safe patient care during cardiac surgery procedures.1,2 Inadequate control of surgical pain can lead to chronic pain in up to 20% of post-sternotomy and 25 to 60% of postthoracotomy patients. Regional techniques may help to reduce acute postoperative pain, including opioid-induced hyperalgesia and the development of chronic pain by reducing noxious sensitisation. Poorly controlled pain is associated with sympathetic nervous system activation and an increased hormonal stress response. This response may contribute to multiple adverse postoperative events, including myocardial ischaemia, cardiac arrhythmias, hypercoagulability, pulmonary complications and increased rates of delirium and wound infection.3 Huang et al. reviewed the incidence of pain at two months after cardiac surgery and found that out of 244 patients, 30% had persistent sternal pain, 29% had continued chest pain after mini-thoracotomy, 17% had shoulder pain and 15.9% had back pain after cardiac surgery.4 Fascial plane blocks involve the deposition of local anaesthetic (LA) between the fascial layers, thereby blocking sensory nerve fibres that pass through the fascial planes and pierce different muscle layers to finally supply cutaneous sensory innervation. The nerve often gives off sensory and motor branches to the muscle layers along its course. With ultrasound guidance, the procedure is relatively simple with a low risk profile. Neuraxial regional anaesthesia, like spinals or epidurals, carries an uncomfortably high perceived risk in terms of nerve injury due to compressive haematoma in a fully heparinised patient. With these techniques, there is also the risk of potential haemodynamic instability at the spinal analgesia level, which is required. Pectoral blocks (PECS I and PECS II) have been used in breast surgery, as described by Blanco, and more recently introduced to cardiac surgery (Fig. 1).5 The medial (C8–T1) and lateral (C5–C7) pectoral, long thoracic (C5–C7) and thoracodorsal (C6–C8) nerves originate from the brachial plexus and provide primarily motor innervation to the muscles of the chest wall, but also carry sensory nerve fibres. Segmental thoracic sensory innervation of the chest wall extends from the spinal nerve root level T1 to T11. The spinal nerve exits the intervertebral foramen and divides into a dorsal and ventral ramus within the paravertebral space, which communicate with the sympathetic trunc via the white and gray rami communicantes. Dorsal rami supply the muscles, bone, joints and skin of the midback. Ventral rami travel alongside blood vessels between pleura and endothoracic fascia, then between internal and innermost intercostal muscles, supplying the lateral and anterior chest wall. At the mid-axillary level, a branch pierces the internal and external intercostal muscles and serratus anterior muscle (SAM), becoming the lateral cutaneous branches providing sensory innervation to the lateral chest wall. The rest of the nerve courses anteriorly towards the sternum and pierces the internal intercostal muscle, external intercostal membrane and pectoralis major muscle, providing sensory innervation for the anterior chest wall. The intercostal nerves provide segmental innervation with an overlap between the adjacent nerves, requiring blockade of at least the nerve above and below. The PECS I block is performed by injecting LA between the pectoralis major and minor muscle at Morheim’s pouch. The ultrasound probe is first placed below the mid-clavicle and moved inferolaterally to the level of the third rib. The thoraco-acromial artery may be seen between the pectoralis major and minor Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa Renier Verbeek, MD Felipe Montoya, MD Justiaan LC Swanevelder, MD, Justiaan.swanevelder@uct.ac.za Fig. 1. Transverse chest anatomy.
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